1. Field of the Invention
The invention is directed to a steel making plant with a double furnace arrangement and a process for operating such a plant.
2. Description of the Prior Art
With the scarcity of energy sources and material growing more acute, there have been a number of suggestions for modelling the production of steel economically and in the most environmentally safe manner. Among these suggestions are the known steps for using the furnace gases extracted from the electric furnace for preheating the charging material. In so doing, the charging material, particularly scrap, is normally preheated in a charging basket.
Such a device is known from the German Patent 33 07 400. In this device, the warm waste gases of an arc furnace can be piped to the basket by means of a feed line and can flow through the scrap in the basket so as to heat it, then be returned subsequently to a gas purification installation.
In another process known from the German Patent 35 21 569, the basket which is filled with scrap is inserted into a preheating oven. This preheating oven is occupied by preheating gas which is heated via a treat exchanger. Tire furnace gas extracted from an electric furnace is guided on its way to the dust-removing installation by the heat exchanger.
The subject matter of both patents mentioned above requires a high construction cost and an abundance of maintenance-intensive structural component parts. Moreover, the repeated refilling of the charging material in various vessels leads to a reduction in the energy which can be exploited from the flue gases.
As concerns the use of more than one furnace, suggestions are known for decreasing the quantity of subassemblies or component groups belonging to the furnace. Thus, it is known from the German Patent 32 25 514 to provide a swivelable cover in a double-hearth arc furnace jointly for both furnace hearths, which cover can be placed on one of the two hearths alternately. This complicated and sensitive construction requires not only high maintenance costs but leads continually to obstructions in the production process.